1. Field of the Invention
The present invention relates generally to a vehicle, such as a bicycle, motorcycle, etc., and, more specifically, to a damper for use in a front fork of the vehicle.
2. Description of the Related Art
A hydraulic shock-absorbing damper of bicycle front fork forces the internal fluid to change the flowing path upon relative movement between the upper front fork tube and the lower front fork tube, thereby absorbing shocks. However, this shock-absorbing damper absorbs active force from the pedals when the rider riding the bicycle upwards on a slope, giving a burden to the rider.
Therefore, an improved design of front fork shock-absorbing structure is developed to eliminate the aforesaid problem. This improved design of front fork shock-absorbing structure allows the bicycle rider to control the structure to work or not to work subject to different road conditions. According to this design, a control rod is provided and movable between a first position where the bottom end of the control rod blocks the fluid passage to prohibit flowing of the fluid between the upper front fork tube and the lower front fork tube, and a second position where the fluid passage is fully opened for enabling the fluid to circulate between the upper front fork tube and the lower front fork tube. This design of front fork shock-absorbing structure is still not satisfactory in function. Because the control rod is adapted to block the fluid passage directly, it directly receives upward impact pressure from the fluid during relative emotion between the upper front fork tube and the lower front fork tube when the rider riding the bicycle over an uneven road surface. Frequently receiving upward impact pressure from the fluid may cause the parts of the control rod to loose. Further, because the device for controlling the position of the control rod is usually provided at the bottom side of the front fork, it is inconvenient to adjust the position of the control rod.